Platelet Activation Mechanism in Microchannel Networks

Abstract

Activation of platelet is the primary response to the scar or inflammation of blood vessel and trigger clotting, thrombus formation and other repairing mechanism. However vascular abnormality such as stenosis can cause uncontrolled activation cause various vascular diseases. The objective of this research is to determine correlation platelet activation with various fluid dynamic parameters and thrombus formation in microchannel network. PDMS mcirochannel network with different width and depth was fabricated using photolithographic process and plasma bonding. Microchannel network mimic Willis circle and various flow conditions including steady and time dependent pulsating flow were investigated. Platelets was flown through the microchannel network loop for 10 min and collected. Platelet activation was quantified by measuring P-selectin expression through FITC-anti-P-selecting and a flow cytometer. The results show that higher flow rate and abrupt changes in vessel diameter leads to an activation in platelets. The abrupt changes in vessel diameter causes vortices in flow, higher shear rate and wall shear stress. This results provide insight on platelet activation and thrombus formation in microvessel such as deep vein thrombosis.